Late Monday, House Democrats learned that Republican leadership had again privately raised the spending cap with attorney Paul Clement and the Washington-based law firm Bancroft LLC to defend DOMA in the U.S. Supreme Court.

A spokesperson for the House Bipartisan Legal Advisory Group (BLAG) confirmed that Rep. Candice Miller (R-Mich.), Chair the House Administration Committee, signed an updated contract to increase the spending cap to $3 million. Previously, the cap was $2,750,000.

The revised contract reads, in part:

“It is further understood and agreed that, effective January 4, 2013, the aforementioned $2,750,000.00 cap may be raised from time to time up to, but not exceeding, $3,000,000.00, up on written notice of the General Counsel to the Contractor specifying that the General Counsel is legally liable.”

The spending increase comes just days after GOP leaders acted to insert language to the Opening Day Rules Package establishing that BLAG “continues to speak for, and articulate the institutional position of, the House in all litigation matters in which it appears, including in Windsor v. United States.”

House Democratic leaders slammed Speaker John Boehner (R-Ohio) on Tuesday for secretly raising the spending cap — the third time the contract has been adjusted since it original $500,000 cap.

“From the start, the Republican-led campaign to defend DOMA has been a practice in futility and a waste of Americans’ hard-earned tax dollars,” Minority Leader Nancy Pelosi (D-Calif.) and Minority Whip Steny Hoyer (D-Md.) said in a letter to Boehner.

“We believe it is only a matter of time before this offensive law is a discarded relic of a bygone era,” Pelosi and Hoyer wrote. “We look forward to the day when this measure is declared unconstitutional by the highest court in the land and when all of America’s families can know the blessings of equal protection under the law.”

DOMA is the federal law defines marriage as the legal union of one man and one woman for federal for all federal purposes, including insurance benefits for government employees, Social Security survivors’ benefits, immigration, and the filing of joint tax returns.

In March, the Supreme Court is scheduled to hear Windsor v. United States, a challenge to DOMA brought upon by Edie Windsor, a widowed lesbian.